Physics, 02.03.2020 23:41, grosst4333

To measure the coefficient of kinetic friction by sliding a block down an inclined plane the block must be in equilibrium.
What experimental condition must you try to accomplish that will assure you that the block is in equilibrium?

a. The block must slide down with a constant speed.
b. The block must slide down with a constant acceleration.
c. The block must be at rest.
d. The block must slide down with an acceleration of 9.8 m/s².

Answers: 1

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answered: Leilaniabma

Explanation:

A block sliding down an inclined plane, is subject to two external forces along the slide.One is the component of gravity (the weight) parallel to the incline.If the inclined plane makes an angle θ with the horizontal, this component (projection of the downward gravity along the incline, can be written as follows:

$F_{gp} = m*g* sin \theta (1)$

(taking as positive the direction of the movement of the block)

The other force, is the friction force, that adopts any value needed to meet the Newton's 2nd Law.When θ is so large, than the block moves downward along the incline, the friction force can be expressed as follows:

$F_{f} = \mu_{k} * N (2)$

The normal force, adopts the value needed to prevent any vertical movement through the surface of the incline:

$N = m*g* cos \theta (3)$

In equilibrium, both forces, as defined in (1), (2) and (3) must be equal in magnitude, as follows:

$m*g* sin \theta = \mu_{k} * m*g* cos \theta$

As the block is moving, if the net force is 0, according to Newton's 2nd Law, the block must be moving at constant speed.In this condition, the friction coefficient is the kinetic one (μk), which can be calculated as follows:

$\mu_{k} = tg \theta$

answered: Guest

weight of the box is given as

$w = 112.1 n$

here this is placed on the inclined of angle 42 degree

now this weight will have two components one is along the incline other is perpendicular to it

so here we need to apply a force parallel to incline opposite to its component of weight

so here the component of weight is given as

$w_x = w sin\theta$

here we have

$w = 112.1 n$

$w_x = 112.1 sin42$

$w_x = 75 n$

so it requires 75 n force to move it upwards

answered: Guest

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